Below I introduce briefly methodological approaches and some key concepts relevant to genetic psychophysiology. Essentially, genetic psychophysiology is an application of human genetics methods to psychophysiological phenotypes; therefore, methodological approaches and problems are largely the same as in other areas of human genetic research dealing with complex phenotypes. Unlike classical “Mendelian” phenotypes that show a simple mode of inheritance and a relatively straightforward relationship between the phenotype and a single gene, a complex phenotype is a product of many genes and environmental factors, and the relationship between genotype and phenotype usually involves multiple mediating pathways and mechanisms. With rare exceptions, most psychophysiological indicators of individual differences are complex phenotypes.
